4.7 | Intracellular delivery of β-Gal
PCNDs were prepared using DPPC, DPPE-PEG-OMe, DPPE-PEG-biotin, and DPPE-PEG-PyDTP as the lipid coating and suspended in 1 μM β-Gal solution, followed by mechanical rotation in a refrigerator (4 °C) for 1 h. After centrifugation and washing, 9E5-conjugation for the PCNDs was performed as described above. After centrifugation and washing, β-Gal- and 9E5-conjugated PCNDs were suspended in RPMI1640-based culture medium. DLD1 cells were treated with β-Gal- and 9E5-conjugated PCND suspension for 3 h under culture conditions. After washing the dish surface, the cells were exposed to ultrasound (5 MHz) using a previously reported method[30,31]. After ultrasound exposure, the cells were stained with TG-βGal and LysoTracker Blue for 1 h under culture conditions. After washing the dish surface, the cells were observed under a confocal microscope, as described above. The fluorescence of TG-βGal (Em: 505/525 nm) and LysoTracker Blue (Em: 410/460 nm) was observed using excitation lasers at wavelengths of 488 and 405 nm, respectively.